42 строки
1.4 KiB
C#
42 строки
1.4 KiB
C#
using System;
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using System.Threading;
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using System.Threading.Tasks;
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using Microsoft.Graphics.Canvas;
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using Microsoft.Graphics.Canvas.Text;
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using Microsoft.Graphics.Canvas.UI.Xaml;
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namespace Xamarin.Forms.Platform.UWP
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{
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public sealed class FontImageSourceHandler : IImageSourceHandler
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{
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float _minimumDpi = 300;
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public Task<Windows.UI.Xaml.Media.ImageSource> LoadImageAsync(ImageSource imagesource,
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CancellationToken cancelationToken = default(CancellationToken))
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{
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if (!(imagesource is FontImageSource fontsource))
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return null;
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var device = CanvasDevice.GetSharedDevice();
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var dpi = Math.Max(_minimumDpi, Windows.Graphics.Display.DisplayInformation.GetForCurrentView().LogicalDpi);
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var canvasSize = (float)fontsource.Size + 2;
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var imageSource = new CanvasImageSource(device, canvasSize, canvasSize, dpi);
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using (var ds = imageSource.CreateDrawingSession(Windows.UI.Colors.Transparent))
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{
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var textFormat = new CanvasTextFormat
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{
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FontFamily = fontsource.FontFamily,
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FontSize = (float)fontsource.Size,
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HorizontalAlignment = CanvasHorizontalAlignment.Center,
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Options = CanvasDrawTextOptions.Default,
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};
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var iconcolor = (fontsource.Color != Color.Default ? fontsource.Color : Color.White).ToWindowsColor();
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ds.DrawText(fontsource.Glyph, textFormat.FontSize / 2, 0, iconcolor, textFormat);
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}
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return Task.FromResult((Windows.UI.Xaml.Media.ImageSource)imageSource);
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}
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}
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}
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